The findings of a phase III trial comparing the efficacy of the second-generation tyrosine-kinase inhibitor (TKI) dacomitinib with that of the first-generation TKI gefitinib in patients with newly diagnosed non-small-cell lung cancer reveal superior progression-free survival in the dacomitinib group (14.7 versus 9.2 months; P <0.0001). However, dacomitinib also substantially increased the risk of grade ≥3 adverse events (in 51% versus 30% of patients), including two treatment-related deaths in the dacomitinib group versus one in the gefitinib group.